Evaluation of the Keystone Diagnostics Quik Test using previously screened urine specimens.

Urine specimens confirmed positive or negative for cocaine, phencyclidine, morphine, and amphetamines by thin-layer chromatography and gas chromatography/mass spectrometry were used in a blind study to evaluate the KDI Quik Test drug screen. Of 10 positive specimens, the KDI Quik Test found 6 to be positive, and of 10 negative specimens, it found 3 positive. In a study of interference, 4 of 10 specimens containing commonly used medications but no cocaine, phencyclidine, morphine, and amphetamine were found positive for the drugs of abuse by the KDI Quik Test.